1. Field of the Invention
The present invention relates to an optical connection sleeve used in optical connection between an optical fiber and an optical component, to an optical module using the same and to an optical communication module.
2. Related Background of the Invention
In an optical communication system such as an optical data link and an optical LAN, in which light is used as an information transmission medium, information is transmitted by transmitting a light signal via an optical transmission path such as an optical fiber transmission path. In such an optical communication system, in order to receive or send the transmitted light signal, an optical communication module including an optical device which converts a light signal and an electric signal mutually is used.
In an optical module such as the foregoing optical communication module, an optical connection sleeve is provided in order to optically connect an optical fiber used for the optical transmission path and an optical component such as the optical device provided in the optical module. In such an optical connection sleeve, optical axes of the optical fiber and the optical device need to coincide with each other precisely in such a manner that a ferrule of a tip of the optical fiber, which is an object of the optical connection, is positioned and fixed with high accuracy with respect to a sleeve previously positioned with the optical device and the like.
As the optical connection sleeve which fixes an optical fiber ferrule with high accuracy as described above, for example, a precision sleeve is used. The precision sleeve is prepared so as to allow an inner diameter of a ferrule fixing surface provided on an inner peripheral surface of a ferrule insertion portion to coincide with an outer diameter of the ferrule with sufficient precision. Then, the optical fiber ferrule is inserted into the ferrule insertion portion, and the ferrule and the sleeve are positioned and fixed by a transition fit.
Moreover, similarly, as the optical connection sleeve which fixes the optical fiber ferrule with high accuracy, a split sleeve is used. The split sleeve is prepared so as to allow the inner diameter of the ferrule fixing surface to be smaller than the outer diameter of the ferrule. Then, the optical fiber ferrule is inserted into the ferrule insertion portion, and the ferrule and the sleeve are positioned and fixed by a tight fit.